There are a variety of solar energy collectors having an energy receiver upon which energy to be collected is directed, where only a portion of the receiver surface has energy directed upon it at a particular instant. Losses result from those portions of the receiver surface which do not have radiation directed thereupon. Heat flows to the unirradiated portions by conduction through the receiver surface from those portions which are irradiated due to the thermally interconnected nature of prior art receivers, and by convection from the hot fluid circulating simultaneously through heated and unheated portions of prior art receivers.
For example, one type of solar collector is the parabolic mirror which directs radiant energy incident thereon to a particular point or focus. Such a mirror is usually stationary and due to the motion of the sun, the focus will move over a particular path each day. With prior art unitized receivers positioned to cover the particular path, only that portion of the receiver upon which the focus was incident would actually be heated. Losses occur from the other portions of the receiver surface not irradiated at a particular instant.
It is therefore an object of this invention to provide an improved solar collector with a high concentration ratio.
Another object of this invention is to provide a nontracking solar concentrator with reduced heat loss from the receiver surface.